JAW050A and JAW075A Power Modules; dc-dc Converters:
36 Vdc to 75 Vdc Input, 5 Vdc Output; 50 W to 75 W
Data Sheet
April 2008
Thermal derating with heat sinks is expressed by using
the overall thermal resistance of the module. Total
module thermal resistance (θca) is defined as the max-
imum case temperature rise (ΔTC, max) divided by the
module power dissipation (PD):
Thermal Considerations (continued)
Heat Transfer Without Heat Sinks (continued)
20
(TC – TA)
------------------------
PD
ΔTC, max
θca = --------------------
PD
18
=
3.0 m/s
(600 ft./min.)
16
14
12
10
8
The location to measure case temperature (TC) is
shown in Figure 18. Case-to-ambient thermal resis-
tance vs. airflow for various heat sink configurations
and heights is shown in Figures 23 and 24. These
curves were obtained by experimental testing of heat
sinks, which are offered in the product catalog.
4.0 m/s
(800 ft./min.)
0.1 m/s
(20 ft./min.)
1.0 m/s
(200 ft./min.)
6
4
2.0 m/s
9
8
(400 ft./min.)
2
0
7
0
10 20 30 40 50 60 70 80 90 100
NO HEAT SINK
6
5
4
3
2
1/4 IN. HEAT SINK
1/2 IN. HEAT SINK
1 IN. HEAT SINK
LOCAL AMBIENT TEMPERATURE, TA (°C)
8-2465(F)
1 1/2 IN. HEAT SINK
Figure 21. Forced Convection Power Derating with
No Heat Sink; Longitudinal Orientation
1
0
20
0
0.5
(100)
1.0
1.5
2.0
2.5
(500)
3.0
18
3.0 m/s
(200)
(300)
(400)
(600)
(600 ft./min.)
16
14
12
10
8
AIR VELOCITY, m/s (ft./min.)
4.0 m/s
(800 ft./min.)
8-2164(F).a
Figure 23. Case-to-Ambient Thermal Resistance
Curves; Longitudinal Orientation
0.1 m/s
(20 ft.min.)
6
1.0 m/s
(200 ft./min.)
4
2.0 m/s
2 (400 ft./min.)
8
7
0
NO HEAT SINK
0
10 20 30 40 50 60 70 80 90 100
1/4 IN. HEAT SINK
1/2 IN. HEAT SINK
1 IN. HEAT SINK
6
5
4
3
2
LOCAL AMBIENT TEMPERATURE, TA (°C)
8-2466(F)
1 1/2 IN. HEAT SINK
Figure 22. Forced Convection Power Derating with
No Heat Sink; Transverse Orientation
Heat Transfer with Heat Sinks
1
0
0
0.5
(100)
1.0
1.5
2.0
2.5
(500)
3.0
The power modules have through-threaded, M3 x 0.5
mounting holes, which enable heat sinks or cold plates
to attach to the module. The mounting torque must not
exceed 0.56 N-m (5 in.-lb.).
(200)
(300)
(400)
(600)
AIR VELOCITY, m/s (ft./min.)
8-2165(F).a
Figure 24. Case-to-Ambient Thermal Resistance
Curves; Transverse Orientation
12
Lineage Power
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
